1. Field of the Invention
The present invention relates to an alumina member suitable for an electrostatic chuck and a heater and to a manufacturing method thereof.
2. Description of the Related Art
Heretofore, in a semiconductor manufacturing process, there has been used an alumina member, such as an electrostatic chuck in which an electrode is embedded in an alumina sintered body, and a heater in which a resistance heating element is embedded in such an alumina sintered body. To each the electrode and the resistance heating element, a terminal for connecting a power supply line thereto is bonded by brazing or the like. Moreover, in the alumina sintered body, a hole for inserting the terminal thereinto is formed (for example, refer to Japanese Patent Laid-Open Publication No. H11-12053 (published in 1999)).
However, the conventional alumina member has had a subject that the terminal and a power-supplied member to be supplied with electric power, such as the electrode and the resistance heating element, are desired to be bonded to each other more firmly. Moreover, there has been a possibility that the formation of the hole, and so on, may bring a strength reduction of the alumina member. In particular, in the case of a Coulomb-type electrostatic chuck, since thickness of a dielectric layer thereof is thin, there has been a possibility that the strength reduction may be brought.